GEN-MKT-18-7897-A
Aug 23, 2019 | Blogs, Environmental / Industrial, Food / Beverage | 0 comments
The BasicsIn today’s busy analytical laboratories, productivity and high sample throughput are constant demands. More samples need to be analyzed in a shorter timeframe. Laboratories must work to use equipment at its maximum capacity, and methods must be optimized.
With liquid chromatography-mass spectrometry (LC-MS), the chromatography separation has the capacity to resolve a certain number of compounds in a specified period of time. Generally, the shorter the LC run time, the poorer the chromatographic resolution. This potentially affects the MS data quality for those analytes. This is true even for high capacity LC columns, such as those for ultra-high-performance liquid chromatography (UHPLC).
With an MS detector—let’s say a triple quadrupole MS—you can overcome some of the chromatography shortfalls by using a highly-specific data acquisition method such as Selected Reaction Monitoring (SRM). This is also known as Multiple Reaction Monitoring (MRM) when more than one reaction is involved. The approach allows compounds to be identified and tracked by a specific precursor to product ion transition, or MRM. As the term “multiple” suggests, you can run concurrent compound transitions in virtually the same time frame (within a few milliseconds). Because each transition is unique to a compound, MRM is a highly specific, sensitive, and efficient way of quantifying an analyte.
With a SCIEX triple quadrupole, the unique features of the acquisition software allow the method to be finely optimized to achieve the right number of data points for accurate and precise quantification of chromatographic peaks. This is a feature called Scheduled MRM™ Pro algorithm. It provides a very efficient way of analyzing 100s of analytes within the necessary duty cycle.
The Polarity QuestionWhat if you need a single LC-MS/MS method to analyze compounds with positive and negative ionization states simultaneously? And what if you need to look at both ionization modes while maintaining a high duty cycle, high selectivity, high sensitivity, and chromatographic peak shape integrity?
Well, MS instruments such as the mid-range SCIEX Triple Quad™ 5500+ LC-MS/MS System – QTRAP® Ready or high-end SCIEX Triple Quad™ 6500+ LC-MS/MS System. Both these instruments have detector technology that allows a single method with positive/negative ion switching to run without compromising your data quality.
In the past, MRM conditions were optimized by choosing dwell times that wouldn’t affect the duty cycle of the experiment—which reduced sensitivity and affected detection levels. This generally meant, shorter dwell times for a particular MRM would result in lower accuracy in peak detection and a much higher detection limit.
With the new data acquisition architecture, excellent software algorithms, and powerful electronics, both the SCIEX 5500+ and 6500+ systems can reduce the polarity switching time from 50 milliseconds to 5 milliseconds while maintaining performance characteristics. This ultimately gives an analytical chemist the ability to analyze more compounds in the same amount of time!
See it in action with these workflows:
SCIEX 5500+ System
SCIEX 6500+ System
The Echo® MS+ system is a novel platform for Acoustic Ejection Mass Spectrometry (AEMS) and combines the speed of acoustic sampling with the selectivity of mass spectrometry. This platform has been designed for high throughput analysis of small and large molecules. The technology combines Acoustic Droplet Ejection (ADE), an Open Port Interface (OPI) and could be coupled with the SCIEX Triple Quad 6500+ system or the ZenoTOF 7600 system.
The Echo® MS+ system comprises of an open-port interface (OPI) and acoustic droplet ejection (ADE) module which could be coupled with a mass spectrometer. The mass spectrometer could either be a SCIEX Triple Quad 6500+ system or the ZenoTOF 7600 system. This non-liquid chromatography based; high-throughput screening platform enables rapid analysis of compounds at speeds of up to 1 sample/second.
The ability to consistently achieve reproducible results on many complex samples across multiple days is critical to a routine clinical laboratory. Laboratories relying on analytical instrumentation require stability and robustness to perform a variety of screening and confirmatory assays with confidence. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become the preferred analytical method in the clinical laboratory to reliably perform clinical testing as it provides best-in-class performance and reliability for the most challenging assays. LC-MS/MS offers the required levels of sensitivity and specificity for the detection and quantitation of molecules from complex biological samples, helping laboratories deliver highly accurate data for a variety of clinically relevant analytes across a wide range of assays.
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